Python single-Link list instance sharing

implementation code for the Python single-linked list.

Definition of a linked list:
A linked list (linked list) is a data structure consisting of a set of data elements called nodes, each of which contains information about the node itself and the address that points to the next node. Since each node contains address information that can be linked, a variable can be used to access the entire sequence of nodes. In other words, the node contains two pieces of information: the value that is used to store the data element, called the information field, and a pointer to store the address of the next data element, called the pointer field. The address of the first node in the list is stored in a separate node, called the head node or the first node. The last node in the list has no successor element, and its pointer field is empty.
Python single-linked list implementation code:

#!/usr/bin/python#-*-coding:utf-8-*-#www.jbxue.comclassNode (object):def __init__(self,val,p=0): Self.data=Valself.next=Pclasslinklist (object):def __init__(self): Self.head=0def __getitem__(self, key):ifself.is_empty ():Print 'linklist is empty.'returnelifKey <0orKey >self.getlength ():Print 'The given key is error'returnElse:returnSelf.getitem (Key)def __setitem__(self, Key, value):ifself.is_empty ():Print 'linklist is empty.'returnelifKey <0orKey >self.getlength ():Print 'The given key is error'returnElse: Self.delete (key)returnSelf.insert (Key)definitlist (self,data): Self.head=Node (data[0]) p=Self.head forIinchData[1:]:node=Node (i) P.next=NODEP=P.nextdefgetlength (self):p=Self.headlength=0 whilep!=0:length+=1P=P.nextreturnlengthdefIs_empty (self):ifSelf.getlength () = =0:returnTrueElse:returnFalsedefClear (self): Self.head=0defAppend (self,item): Q=Node (item)ifSelf.head = =0:self.head=QElse:p=Self.head whilep.next!=0:p=P.nextp.next=QdefGetItem (self,index):ifself.is_empty ():Print 'linklist is empty.'returnJ=0p=Self.head whileP.next!=0 andJ <index:p=P.NEXTJ+=1ifj = =Index:returnP.dataElse:Print 'target is not exist!'defInsert (Self,index,item):ifSelf.is_empty ()orIndex<0orIndex >self.getlength ():Print 'linklist is empty.'returnifindex = =0:q=Node (item,self.head) Self.head=QP=Self.headpost=Self.headj=0 whileP.next!=0 andj<Index:post=pp=P.NEXTJ+=1ifindex = =J:q=Node (item,p) Post.next=Qq.next=PdefDelete (self,index):ifSelf.is_empty ()orIndex<0orIndex >self.getlength ():Print 'linklist is empty.'returnifindex = =0:q=Node (item,self.head) Self.head=QP=Self.headpost=Self.headj=0 whileP.next!=0 andj<Index:post=pp=P.NEXTJ+=1ifindex = =J:post.next=P.nextdefIndex (self,value):ifself.is_empty ():Print 'linklist is empty.'returnP=Self.headi=0 whileP.next!=0 and  notP.data = =value:p=P.nexti+=1ifP.data = =Value:returnIElse:return-1L=linklist () l.initlist ([1,2,3,4,5])PrintL.getitem (4) L.append (6)PrintL.getitem (5) L.insert (4,40)PrintL.getitem (3)PrintL.getitem (4)PrintL.getitem (5) L.delete (5)PrintL.getitem (5) L.index (5)

Results:

5
6
4
40
5
6

Python single-Link list instance sharing